A voltage regulator module provides a stable operating voltage for CPU mainly through the conversion of DC-to-DC voltage, wherein the input voltage is generally 12V DC voltage, the output voltage is generally a low-voltage and the output current is high (the output voltage is generally about 1.8V, and the current is generally not below 100 A). In addition, the voltage regulator module is generally required to have high efficiency, a high power density, a small size, a low height and so on.
In order to achieve high efficiency, a high power density, a small size and a low height, the first method known to the inventors is to realize a voltage regulator module by using a multiphase interleaved buck circuit which is generally designed to have a high frequency, thereby greatly reducing the size and height of a magnetic component. The second method known to the inventors is to replace the traditional discrete MOSFET components to Driver+MOSFET integrated components in a voltage regulator module. The third method known to the inventors is to realize a voltage regulator module by using the technology of magnetic integration.
The voltage regulator module is not only required to have a small size but also required to have a low height. In general, in a voltage regulator module, the height of an inductor is far higher than the height of a common semiconductor component whose height is usually about 1 mm. In order to reduce the height of the whole product, how to reduce the height of the inductor has become a problem that must be considered during design.
Referring to FIG. 1, FIG. 1 is a side view of an inductor structure as conventionally known in the art. As shown in FIG. 1, the inductor structure includes a PCB board 11 and a magnetic core 12. The PCB board 11 is provided with a plurality of through holes spaced apart, and the magnetic core 12 is inserted into the plurality of through holes, the copper foil in the PCB board is used as the coil of the inductor structure, the overall height of the product is generally lower than that of a product using a conventional discrete inductor. However, the thickness of the coil thereof is the thickness of the whole PCB board, and the multi-layer PCB board is relatively thick, e.g., an 8-layer PCB board generally has a thickness of about 2 mm. In this way, the overall height Hd1 of the PCB inductor structure is about 6.3 mm, which cannot meet the height requirements yet in some cases. Therefore, it is imperative to develop an inductor structure that can overcome the above drawbacks.